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ArcticMyst Security by Avery

CR2 discharge rates? safe for a 1.3-1.6A build?

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May 28, 2011
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Hey everyone, i just finished my 2 CR2 Coleman build with a jibs 1.3-1.6a linear driver...i have green ultra fire 3.0v TR 15270's and blue ultrafire 3.6v LC 15266's...are either of these safe to use in a 1.3+a build?
 





rhd

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In my experience, those blue CR2s are actually quite capable little cells. The green ultrafire 3V cells are essentially junk for our purposes. They've got some sort of circuitry in them to lower their voltage, the side-effect of which is that they struggle providing higher current levels. Also, with the dropout of the driver considered, a 3V x2 setup isn't appropriate anyway.

Use the blues. Just be aware of when they start getting hot, as I've noticed that they have a tendency to get so hot that their blue shrink-wrap casing pulls up and exposes their metal shell.
 
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Ohh..okay....that saves me money. Is the diode a 4v diode? I have a smaller dilda build set at around 500ma. Will the 3v ones work in that? It has a groove 2...
 

rhd

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Is the diode a 4v diode? I have a smaller dilda build set at around 500ma. Will the 3v ones work in that? It has a groove 2...

Diodes don't work like that. They don't have a fixed voltage, they have current/voltage (or a "PIV") curve. You can search for them on this forum, they've been posted a few times.

The answer is just math:

Total voltage of batteries - dropout of your driver = voltage left for your diode.

If that number is higher than the voltage your diode requires at the current you're seeking, then you're good.
 
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Oh, I honestly am still learning how everything works...i see tough....thanks! i found the charts. and i understand them too...the groove has a low dropout so the 3.0's will work for the dilda at the low current...thanks!
 

SHIN

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Hi.
The capacity of 3.7V CR2 rechargeable (15270, 15260) is 300mAh - 350mAh.
2C of this is under 700mA.

CR2 has no protection board AFAIK.
I think there will be over-discharge problem frequently. (CR2 rechargeable will be easily dead at high current device.)

I recommend the larger capacity Li-ion for your laser.

SHIN
 
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SHIN

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Hi. DTR.

That is best one!
AW 16340 is either IMR or protected Li-ion.

But AW CR2 is not protected, not IMR....

Please let me know if you know "a protected CR2". DTR.:)

SHIN
 
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wait, that battery says its an r123...im using cr2's.....will it fit in place of the cr2's?
 

rhd

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As far as I know, any time you see a 3.0 or 3.2 V CR2 lithium ion, you're really seeing a cell with a weird hybrid protection / step-down circuit.
 

rhd

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wait, that battery says its an r123...im using cr2's.....will it fit in place of the cr2's?

No -

R123 = CR123 = CR123A = RCR123 = RCR123A = 16340

CR2 = 15270 = 15266
 
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SHIN

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You can PM to AW@CPF.

He is a famous supplier of Li-ion @ CPF.
 

DTR

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Hi. DTR.

But AW CR2 is not protected, not IMR....

Please let me know if you know "a protected CR2". DTR.:)

SHIN

Yea you are right they are not protected. I am thinking of the black ones.


wait, that battery says its an r123...im using cr2's.....will it fit in place of the cr2's?

The 16340 is bigger than the standard CR2.
What actual host are you using?
 




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